Process of removing color developer stain in azine dye images



Patented Oct. 27, 1953 PROCESS OF REMOVING COLOR DEVEL- OPER STAIN INAZINE DYE IMAGES James E. Bates, Chenango Bridge, N. Y., assignor toGeneral Aniline & Film Corporation, New York, N. Y., a corporation ofDelaware N Drawing. Application December 22, 1950, Serial No. 202,437

6 Claims.

This invention relates to photographic rinse baths for removing colordeveloper stains from azine dyestuif images following color formingdevelopment with ZA-diaminoaniline developing agents.

It is known that azine dyestuif images are produced by color developingsilver halide emulsions containing azine color formers with aZA-diaminoaniline developing agent. The procedure of this process isfully described in U. S. P. 2,486,440.

Despite the many recognized advantages of this process, theZA-diaminoaniline developing agents employed therein possess onedisadvantage which causes a somewhat serious problem. The disadvantageoccurs in the development of the multilayer color film of the azine typeand is manifested especially when the aromatic trianiino developingsolution is old and badly oxidized by leaving a developer stain in theprocessed film. This stain in most cases is quite substantive to gelatinbut can under certain circumstances be to some extent removed byexcessively long water washing after color development. This developerstain is observed particularly in the highlights or Whites of theprocessed film. In the color developed areas of the film, it produces aserious loss in color brilliance and a degradation of color rendition.Moreover, the developer contributes in no small degree to the loss ofstorage stability of the final color image, including both the socalledlight, humidity, and heat fading characteristics.

In a multi-layer color film of the azine type which is composed of threelayers colored yellow, magenta, and cyan, an ideal red reproductionwould be composed of images wholly contained in the yellow and magentalayers and with a minimum of density in the cyan layer. Inasmuch as2,4-diaminoanilines, as a general class, are oxidized quite readily byair and the residual color developing agent is oxidized by the bleachingsteps subsequent to normal color development, an appreciable degradationof the red manifests itself by a stain density formed in the cyan layer.

To overcome the excessive washing time and the formation of stain, rinsebaths consisting of aqueous solutions of water soluble open-chain mono-,di-, and tribasic acids, such as acetic,

citric, maleic, etc., have been suggested. Shortstop baths containingthese acids are, however, ineffective when applied to the azine processsince they minimize the solubility of the 2,4- diaminoaniline colordevelopers and lead to a product of extremely poor color rendition.Rinse baths of aqueous solutions of aliphatic aldehydes 2 and diketones,such as formaldehyde, paraformaldehyde, and the like, have also beenproposed but these are also ineffective since a falsification of coloroccurs.

It is an object of the present invention to provide a simple andeconomical method of eliminating color stain and degradation from azinedyestufi images obtained by color forming development with2,4-diaminoaniline developing agents. Other objects and advantages willappear hereinafter.

The above objects are accomplished by treating an azine multilayer colorfilm, after color forming development with an aqueous rinse bathcontaining from 0.1 to 10% of formaldehyde and from 0.1 to 10% of aWater-soluble acid, such as hydrochloric, phosphoric, acetic, maleic,citric, acrylic, oxalic, tartaric, and the like. The pH of the resultingrinse bath is immaterial and in these concentrations, and in thepresence of formaldehyde, the acid does not form an insoluble complexwith the residual ZA-diaminoaniline developing agent retained by thefilm, i. e., does not precipitate it upon the film or in the layersthereof. The presence of the Water-soluble acid tends to cause theformaldehyde to form a watersoluble 2,4-diaminoaniline-formaldehydecomplex which is readily washed from the emulsion by one or two waterrinses after the processing steps have been completed.

The 2,4-diaminoanilines which are utilized as the color developers forthe production of azine dyestufi images are of the type described in theaforementioned Patent 2,486,440 and in application Serial No. 101,913,filed June 28, 19%, now Patent No. 2,570,116, and entitled ColorDevelopers for the Production of Azine Dye Images." Specific examples ofsuch developing agents are:

-(B-hydroxyethylamino) 6 (4'-carb0xymethoxyphenylamino) -metanilic acid-(carboxymethylamino) 6 (i-'-methoxyphenylamino) -metanilic acid 2-s-sulfoethylamino) -4-phenylamino aniline 4,6-di(/s-hydroxyethylaminol-metanilic acid 4-(5 hydroxyethylamino) -6phenylamino-metanilic acid.Z-(B-hydroxyethylamino) 4 (fi sulfoethylamino) -5-methy1 aniline4-(B-hydroxy-e-methylethylamino) 6 phenylamino-metanilic acide-ls-dflhydroxyethyl)ethylaminol 5 (3-ethoxyphenylamino) -metanilic acid4-(5 hydroxyethylamino) 6 methylaminometanilic acid 4-(sulfomethylamino)6 methylphenylaminometanilic acid -(c hydroxyethylamino) 6methylaminometanilic acid Color formers which are used with theaforementioned developers to give yellow azine dye images are alsodescribed in the aforementioned application Serial No. 101,913. Thesecompounds are typified by the fact that they are open-chainketomethylene compounds. Examples of such compounds are:

Acetoacetanilide N- l -naphthylacetoacetamide N,N'-ethylenebisacetoacetamide p,p'-bi o-acetoacetanisideN-2-naphthylbenzoylacetamide p,p -bi-acetoacetanilidea,a-terephthaloylbis (3 chloro 4,6 dimethoxyacetanilide)a-benzoylacetaniiide Preferably, the color formers utilized contain agroup rendering them non-migratory in the emulsion. Examples of suchcompounds are:

2 (m benzoylacetamidophenyl) l octadecyl- 5-benzimidazolesulfonic acid3,3 ureylenebis 5 p benzoylacetamidobenzamide-benzenesulfonic acid 2 pbenzoylacetamidobenearnido 6 stearoylamino-p-toluenesulfonic acid 2 (pbenzoylacetamidophenyl l octadecyl- 5-benzimidazo1esulfonic acid pcyanoacetyl 3 octadecenylsuccinalic acid.

Color formers capable of producing magenta dyestuff images are alsodescribed in the above identified application and in USP 2,524,741.Preferably, these color formers are 6-halogen-8-hydroxyquinolines, andparticularly those which are non-migratory in the emulsions. Examp1es ofthe latter type compounds are:

6 stearoylamino 2 (2 phenyl 6 bromo- 8' hydroxycinchoninoyl)aminotoluene 4- sulfonic acid 2 phenyl 6 chloro 8hydroxycinchoninoyloctadecyl taurine 6 decoxy 3 (2 phenyl 6 bromo 8hydroxycinchoninoyl) amino benzenesulfonic acid.

2 (3 stearoylaminophenyl) 6 bromo 8- hydroxycinchoninic acid 2stearoylamino 6 (6 chloro 8 hydroxycinchoninoyl) aminotoluene 4 sulfonicacid, and the like.

Color formers for the cyan image are also described in USP 2,570,1 6,issued October 2, 1951, and in USP 2,445,252, issued July 13, 1948.Preferably, these color formers are aryl-J-acid derivatives,particularly those containing a group rendering the color formernon-migratory in the emulsion. Examples of the latter compounds are:dodecyl urethane of fi-sulfoethyl-J-acid tetradecyl urethane ofp-anisyl-J-acid Z-hexadecyl urethane of phenyl-J-acid4-stearoylamino-J-acid, and the like.

By employing an acidified formaldehyde solution, a substantialimprovement in color brilliance and rendition is obtained. This isattributable to the fact that formaldehyde forms a highly solublecomplex with the color developer in an acid solution, and as aconsequence, reduces color degradation and leads to improved colorbrilliance.

The following examples describe in detail the method for accomplishingthe above objects. It is to be understood, however, that they areexemplary only and they are not to be construed as being limitative.

Example I A red sensitive emulsion containing phenyl-J- acid-N-octadecylurethane was exposed and the latent image developed in a black and whitedeveloper, re-exposed, and the residual silver halide developed in asolution of the following composition:

Grams Sodium carbonate (monohydrate) 40 Sodium sulfite 40 Sodium sulfate50 Ethylenediamine l5 Z-aminopyridine 10 4 (B hydroxyethylamino) 6methylamino-metanilic acid 5 Water to make 1000 cc.

After color development, the layer was rinsed, and treated for 5 minutesin a bath of the following composition:

Hydrochloric acid grams 5 Formaldehyde 0% aqueous solution) cc 10 Waterto make 1000 cc.

The film was washed, bleached in a ferricyanide bleach, and fixed in anacid hardening solution. There is obtained a cyan positive dye imagecompletely free from stain and stable against accelerated adversestorage conditions.

Example I I Grams Sodium carbonate (monohydrate) 40 Sodium sulfite 60Potassium bromide 5 Pyridine 16 Benzylamine 1 4 (B hydroxyethylamino) 6phenyl amino-metanilic acid 5 Water to make 1000 cc.

After color development, the film was rinsed and treated for 5 minutesin a bath of the following composition:

Acetic acid grams 10 Formaldehyde l0% aqueous solution) cc 40 Water tomake 1000 cc.

The film was washed, bleached in a ferricyanide bleach, and fixed in anacid hardening fixer solution. There was obtained a multicolor filmcontaining stain-free positive dye images of excellent brilliance andfreedom from color degradation.

Example III An integral tripack of essentially the same composition asin Example II was exposed and color developed for minutes to a negativeimage in a solution of the following composition:

Grams Trisodium phosphate Sodium sulfite 40 Potassium bromide 12.5

Hydroxylamine hydrochloride 1 4 4,8 hydroxyethylamino) -6-benzylamin0-metanilic acid 6 Water to make 1000 cc.

After development, the film was rinsed and treated in a bath of thefollowing composition:

Citric acid grams 10 Formaldehyde (40% aqueous solution) cc 20 Water tomake 1000 cc.

The film was washed, bleached in a ierricyanide bleach, and fixed in anacid hardening hypo solution. There was obtained a brilliant negativedye image completely free from stain and color degradation. The negativedid not acquire additional stain nor become subject to color degradationduring three weeks accelerated aging at relative humidity and F.

It will be obvious to any one skilled in the art that manymodifications, such as substituting equivalent materials and varying theproportions of materials used, are within the spirit and scope of theinvention as defined in the appended claims.

I claim:

1. In the process of eliminating stain in the production ofsubtractively colored azine dye images in a silver-halide emulsioninvolving ex- 'posure of said emulsion, color developing the same in aZA-diaminoaniline developer in the presence of a color former to producea subtractively colored azine dye image, bleaching, fixing and washingsaid emulsion, the improvement which comprises interpolating between thecolor development and bleaching step a rinsing of the color developedemulsion with an aqueous solution containing from 0.1 to 10% offormaldehyde and 0.1 to 10% of a water soluble acid.

2. The process according to claim 1 wherein the acid is acetic.

3. The process according to claim 1 the acid is hydrochloric.

4. The process according to claim the acid is maleic.

5. The process according to claim the acid is citric.

6. The process according to claim 1 the acid is acrylic.

wherein 1 wherein 1 wherein wherein JAMES E. BATES.

References Cited in the file of this patent UNITED STATES PATENTS HarshAug. 15, 1950

1. IN THE PROCESS OF ELIMINATING STAIN IN THE PRODUCTION OFSUBTRACTIVELY COLORED AZINE DYE IMAGES IN A SILVER-HALIDE EMULSIONINVOLVING EXPOSURE OF SAID EMULSION, COLOR DEVELOPING IN THE SAME IN A2,4-DIAMINOANILINE DEVELOPER IN THE PRESENCE OF A COLOR FORMER TOPRODUCE A SUBTRACTIVELY COLORED AZINE DYE IMAGE, BLEACHING, FIXING ANDWASHING SAID EMULSION, THE IMPROVEMENT WHICH COMPRISES INTERPOLATINGBETWEEN THE COLOR DEVELOPMENT AND BLEACHING STEP A RINSING OF THE COLORDEVELOPED EMULSION WITH AN AQUEOUS SOLUTION CONTAINING FROM 0.1 TO 10%OF FORMALDEHYDE AND 0.1 TO 10% OF A WATER SOLUBLE ACID